hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 11 deletions

diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index 4df58b8ea64..68ca5a8704b 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -33,12 +33,12 @@
 void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
 {
 	struct fsnotify_mark *mark, *lmark;
-	struct hlist_node *pos, *n;
+	struct hlist_node *n;
 	struct mount *m = real_mount(mnt);
 	LIST_HEAD(free_list);
 
 	spin_lock(&mnt->mnt_root->d_lock);
-	hlist_for_each_entry_safe(mark, pos, n, &m->mnt_fsnotify_marks, m.m_list) {
+	hlist_for_each_entry_safe(mark, n, &m->mnt_fsnotify_marks, m.m_list) {
 		list_add(&mark->m.free_m_list, &free_list);
 		hlist_del_init_rcu(&mark->m.m_list);
 		fsnotify_get_mark(mark);
@@ -71,12 +71,11 @@ static void fsnotify_recalc_vfsmount_mask_locked(struct vfsmount *mnt)
 {
 	struct mount *m = real_mount(mnt);
 	struct fsnotify_mark *mark;
-	struct hlist_node *pos;
 	__u32 new_mask = 0;
 
 	assert_spin_locked(&mnt->mnt_root->d_lock);
 
-	hlist_for_each_entry(mark, pos, &m->mnt_fsnotify_marks, m.m_list)
+	hlist_for_each_entry(mark, &m->mnt_fsnotify_marks, m.m_list)
 		new_mask |= mark->mask;
 	m->mnt_fsnotify_mask = new_mask;
 }
@@ -114,11 +113,10 @@ static struct fsnotify_mark *fsnotify_find_vfsmount_mark_locked(struct fsnotify_
 {
 	struct mount *m = real_mount(mnt);
 	struct fsnotify_mark *mark;
-	struct hlist_node *pos;
 
 	assert_spin_locked(&mnt->mnt_root->d_lock);
 
-	hlist_for_each_entry(mark, pos, &m->mnt_fsnotify_marks, m.m_list) {
+	hlist_for_each_entry(mark, &m->mnt_fsnotify_marks, m.m_list) {
 		if (mark->group == group) {
 			fsnotify_get_mark(mark);
 			return mark;
@@ -153,8 +151,7 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
 			       int allow_dups)
 {
 	struct mount *m = real_mount(mnt);
-	struct fsnotify_mark *lmark;
-	struct hlist_node *node, *last = NULL;
+	struct fsnotify_mark *lmark, *last = NULL;
 	int ret = 0;
 
 	mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT;
@@ -173,8 +170,8 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
 	}
 
 	/* should mark be in the middle of the current list? */
-	hlist_for_each_entry(lmark, node, &m->mnt_fsnotify_marks, m.m_list) {
-		last = node;
+	hlist_for_each_entry(lmark, &m->mnt_fsnotify_marks, m.m_list) {
+		last = lmark;
 
 		if ((lmark->group == group) && !allow_dups) {
 			ret = -EEXIST;
@@ -194,7 +191,7 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
 
 	BUG_ON(last == NULL);
 	/* mark should be the last entry.  last is the current last entry */
-	hlist_add_after_rcu(last, &mark->m.m_list);
+	hlist_add_after_rcu(&last->m.m_list, &mark->m.m_list);
 out:
 	fsnotify_recalc_vfsmount_mask_locked(mnt);
 	spin_unlock(&mnt->mnt_root->d_lock);